Liquid holding apparatus for insertion of a test device into a test liquid

ABSTRACT

A liquid holding apparatus has a liquid holding device and a backing attached to the liquid holding device. The liquid holding device has a front wall and a rear wall and includes a periphery wherein the front wall and the rear wall are sealed together. The upper section of the liquid holding device has an access section where the front wall can be detached from the rear wall to allow access for a test device. At least a portion of the front wall is substantially transparent. The backing is stiffer than both the front wall and the rear wall.

BACKGROUND OF THE INVENTION

This invention relates to small, portable liquid holding apparatuses used for the insertion of a test device into a test liquid. Small portable liquid holding apparatuses are used for a variety of applications.

In typical applications, liquid holding apparatuses are used in urinalysis (also called a routine urine test) to check for abnormalities in urine. Urine is liquid waste that is made by the kidneys and stored in the bladder until it is eliminated by the body through urination. A number of diseases and conditions can result in abnormalities in the urine. These abnormalities may be detected through physical, chemical, and microscopic examination. Urinalysis may be performed as part of a regular physical examination to screen for early signs of disease.

Urinalysis was the very first laboratory test developed˜the value of urine testing to diagnose medical conditions was established over 6000 years ago. There is evidence of visual testing of urine in the earliest civilizations. As advances in medicine are proved visual testing to be unreliable, chemical evaluation of the urine replaced this method as a more accurate means of diagnosis.

Further understanding of the structure of the body (anatomy) and of the physical and chemical processes involved in organ function (physiology), as well as the invention and development of the microscope, led to additional advances in urine testing as a diagnostic tool. Urinalysis was first introduced as part of the routine physical examination in 1827, and this test remains a valuable method of diagnosis.

Dipstick tests involve placing papers that contain small pads of chemicals into the urine sample. These papers, referred to as urine dipsticks and urine reagent strips, change color when exposed to various substances in the urine. This type of urine testing can result in false-positive or false-negative results. Therefore, most laboratories use urine dipstick controls to determine whether the dipsticks are performing properly.

Urine dipstick controls mimic patient samples and are fortified to target levels with compounds that produce the desired reaction when tested by the dipsticks. This is an accurate means of determining the performance of the dipsticks to insure accurate results from patient specimens. If a dipstick is found to provide inaccurate results, the dipsticks are discarded and a new package is tested. If the dipsticks in the new package perform within specifications, then the dipsticks are used to test actual patient samples. Medical technologists run controls on a daily basis in order to be compliant with state and federal regulations governing quality control in the clinical setting. The controls can be urine or synthetic urine.

Hospital and reference laboratories have used controls for urinalysis dipstick testing for many years. These laboratories typically have large refrigeration units located in close proximity to the actual location where testing is performed. This means that a medical technologist working in the lab would simply remove the control material from the refrigerator as needed. All liquid, ready-to-use, quality control material requires refrigeration in order to achieve maximum stability.

In recent years, a trend towards point-of-care urine dipstick testing has occurred. This means that more testing is being performed by nurses at the point-of-care. Nurses have different needs from medical technologists. One of the most important needs is that they may not have refrigeration suitable to store in-vitro diagnostic products, such as urine dipstick controls. The refrigeration that is available to them is usually dedicated for the storage of items such as medication and food. Therefore, nurses require controls that feature extended room temperature stability. Additionally, nurses require controls that are portable so that they can easily be transported to the point-of-care (bedside, nurses' station, etc.).

There is a need for a liquid holding apparatus which is easier to use and less prone to spilling accidents than liquid holding apparatuses of the prior art.

SUMMARY

The invention satisfies this need. In a first aspect, the invention is a liquid holding apparatus for insertion of a test device into a test liquid, the holding device comprising: (a) a liquid holding device for holding the test liquid, the liquid holding device having an upper section and a lower section, the liquid holding device comprising a front wall with a forward facing surface and a rear wall with a rearward facing surface, the liquid holding device having a periphery wherein the front wall and the rear wall are sealed together at the periphery, the upper section of the liquid holding device having an access section where the front wall can be detached from the rear wall to allow access for the test device, at least a portion of the front wall being substantially transparent or translucent to allow visual inspection of a test device inserted into the liquid holding device; (b) test liquid in the liquid holding device; and (c) a backing attached to at least a portion of the rearward facing surface of the rear wall, the backing being stiffer than both the front wall and the rear wall.

In a second aspect, the invention is method of testing a test device comprising the steps of: (a) holding the liquid holding apparatus described above by the portion of a tab extending above the liquid holding device; (b) opening the access section in the liquid holding device; and (c) inserting the test device into the test liquid.

In a third aspect, the invention is a method of forming the control device described above comprising the steps of: a) laminating the front wall to the rear wall except at the access section to form the liquid holding device; b) placing test liquid into the liquid holding device through the access section; c) laminating the front wall to the rear wall at the access section; and d) laminating the front wall to the rear wall below the access section by with sufficient pressure, temperature and dwell that the seal formed thereby is stronger than the seal at the access section.

DRAWINGS

These and other features, aspects, and advantages of the present invention will become better understood with reference to the following description, appended claims, and accompanying drawings where:

FIG. 1 is a front plan view of a liquid holding device usable in invention;

FIG. 2 is a front plan view of a first liquid holding apparatus having features of the present invention;

FIG. 3 is a cross-sectional view of the liquid holding apparatus illustrated in FIG. 2, taken along line 3-3;

FIG. 4 is a cross-sectional view of the liquid holding apparatus illustrated in FIG. 2, taken along line 4-4;

FIG. 5 is a cross-sectional view of the liquid holding apparatus illustrated in FIG. 2, taken along line 5-5;

FIG. 6 is a front plan view of a second liquid holding apparatus having features of the present invention;

FIG. 7 is a front plan view of a third liquid holding apparatus having features of the present invention; and

FIG. 8 is a front plan view of a test device to be insertable into the liquid holding apparatus of the invention.

DESCRIPTION

The following discussion describes in detail one embodiment of the invention and several variations of that embodiment. This discussion should not be construed, however, as limiting the invention to those particular embodiments. Practitioners skilled in the art will recognize numerous other embodiments as well.

DEFINITIONS

As used herein, the following terms and variations thereof have the meanings given below, unless a different meaning is clearly intended by the context in which such term is used.

The terms “a,” “an,” and “the” and similar referents used herein are to be construed to cover both the singular and the plural unless their usage in context indicates otherwise.

As used in this disclosure, the term “comprise” and variations of the term, such as “comprising” and “comprises,” are not intended to exclude other additives, components, integers, ingredients or steps.

THE INVENTION

In a first aspect, the invention is a liquid holding apparatus 10 for insertion of a test device 12 into a test liquid 14. The liquid holding apparatus 10 comprises a liquid holding device 16, test liquid 14 within the liquid holding device 16 and a backing 18 attached to the liquid holding device 16.

FIG. 1 illustrates one embodiment of the liquid holding device 16. FIGS. 2-5 illustrate a first embodiment of the liquid holding apparatus 10. FIG. 6 illustrates a second embodiment of the liquid holding apparatus 10, and FIG. 7 illustrates a third embodiment of the liquid holding apparatus 10.

The liquid holding device 16 has an upper section 20 and a lower section 22. The liquid holding device 16 also comprises a front wall 24 with a forward facing surface and a rear wall 26 with a rearward facing surface.

In the embodiments illustrated in the drawings, the front wall 24 is sealed to the rear wall 26 along a chevron-shaped weld 27. Above the chevron-shaped weld 27, the front wall 24 is not sealed to the rear wall 26.

The upper section 20 of the liquid holding device 16 has an access section 28 where the front wall 24 can be detached from the rear wall 26 to provide an access opening 29 for allowing access for the test strip test device 12.

At least a portion of the front wall 24 is substantially transparent or translucent to allow visual inspection of a test device 12 inserted into the liquid holding device 16.

The liquid holding device 16 has a periphery 30 wherein the front wall 24 and the rear wall 26 are sealed together at the periphery 30.

When the liquid holding apparatus 10 is used in urinalysis, the liquid holding device 16 is sufficiently long that a test device 12 (which is about 146 mm long, 5 mm wide and 1 mm thick—and having active portions 34, with the portion of the urine reagent strip having the active portions 34 being about 81 mm long) can be dipped in the liquid holding device 16 with all of the active portions 34 in contact with test liquid. Optionally, the liquid holding device 16 is at least 90 mm in length from the access section 28 to the bottom of the liquid holding device 16.

The liquid holding device 16 is preferably sufficiently long that all active portions 34 of the test device 12 can be immersed in the test liquid 14, and wherein the amount of test liquid 14 in the liquid holding device 16 is sufficient small that no test liquid 14 flows out of the liquid holding device 16 when the test device 12 is inserted into the liquid holding device 16 a sufficient distance that all active portions 34 are in contact with the test liquid 14.

The volume of test liquid 14 in the liquid holding device 16 is sufficiently small that a test device 12 can be dipped therein without any test liquid 14 leaking out of the liquid holding device 16. Optionally, the liquid holding device 16 contains test liquid 14 in an amount of no more than about 80% the total capacity of the liquid holding device 16. A minimum for typical urine test strip applications is 0.4 ml to a maximum of 5 ml. Fill volume and liquid holding device 16 geometry may vary depending on the application.

The upper section 20 of the liquid holding device 16 has an access section 28 where the front wall 24 can be detachable from the rear wall 26 to provide an access opening 29 for allowing access for a test device 12.

The front wall 24 is typically attached to the rear wall 26 at the access section 28 by a first lamination 36, and the front wall 24 is attached to the rear wall 26 below the access section 28 by a second lamination 38. In the embodiments illustrated in FIGS. 2-6, the second lamination 38 is made in such a way that striations of the second lamination 38 are disposed perpendicular to the longitudinal axis of the liquid holding device 16. In the embodiment illustrated in FIGS. 2-5, the second lamination 38 is made to only a portion of the liquid holding device 16 below the access section 28. In the embodiment illustrated in FIG. 6, the second lamination 38 is made essentially to the entirety of the liquid holding device 16 below the access section 28. In the embodiment illustrated in FIG. 7, the second lamination 38 is also made essentially to the entirety of the liquid holding device 16 below the access section 28, but in such a way that striations of the second lamination 38 are disposed parallel to the longitudinal axis of the liquid holding device 16.

Preferably, the peel strength of the second lamination 38 is greater than the peel strength of the first lamination 36. By “peel strength” it is meant a material's ability to resist forces that can pull it apart by separating a flexible surface from a more rigid surface. Peel strength is the measure of the average force to part two bonded materials. Peel strength is calculated during a peel test at a constant speed rate by divided the average force required during the test by the unit width of the bonded samples. Depending on materials, norms, products, the tests can be done with different angles. 90° and 180° are commonly used.

Preferably, the first lamination 36 is peelable by finger strength but sufficient to hold liquid and exclude atmospheric gases. The second lamination 38 is not peelable by finger strength, effectively resulting in a stop peel point.

Preferably, the access section 28 provides an access opening 29 which is wider than the liquid holding device 16 below the access section 28 to facilitate test device 12 insertion.

It is also preferable that the width of the liquid holding device 16 is tapered in the portion 32 below the access opening 29, so as to be continuously narrowed toward the end opposite the access section. In the embodiment illustrated in the drawings, the width of the liquid holding device 16 is continuously tapered below the access opening 29. The wider access section 28 provides easy access of a test device 12. The tapering results in less volume, therefore making it less likely that test liquid 14 will spill out. Tapering also cuts down the cost of raw materials.

It is desirable that the materials used for forming the liquid holding apparatus, at least in the region of the liquid holding device 16, be water proof, non-reactive with all the constituents of the test liquid, and substantially oxygen and water vapor impermeable so the test liquid 14 has at least a thirty day useful life without refrigeration. Preferably any portions of the walls in contact with the test liquid 14 are substantially non-reactive with the test liquid.

For long term stability, preferably the walls resist oxygen and water vapor transmission. Preferably the oxygen and moisture barrier ranges are:

-   -   OTR (oxygen transmission rate)—<0.02 cc/100 in2/24 hours @73° F.         (23° C.), 0% RH     -   WVTR (water vapor transmission rate)—<0.16 g/100 in2/24 hours @         100° F. (38° C.), 90% RH

In one embodiment, the front wall 24 is made from an extrusion laminate of three materials pressed together. TABLE 1 lists specifications for a typical such three material laminate:

TABLE 1 Material: .48 MIL HIGH BARRIER POLYESTER/.75 MIL EAA/ 1.5 MIL VARIABLE STRENGTH SEALANT FILM Web: 1.7500 In Cutoff: 5.2308 In

In one embodiment, the rear wall 26 can be an extrusion laminate of five materials pressed together. TABLE 2 lists specifications for a typical such five material laminate:

TABLE 2 Material: .92 MIL COATED POLYESTER/.75 MIL WHITE LDPE/.285 MIL FOIL/.75 MIL WHITE EAA/1.5 MIL VARIABLE STRENGTH SEALANT FILM Web: 1.7500 In Cutoff: 5.2308 In

The composition of both the front wall 24 and the rear wall 26 can include a variable strength sealant film, such as a variable strength film employing a Surlyn® based resin made by E. I. du Pont de Nemours and Company of Wilmington Del. Such variable strength seal can be employed to convenient provided desired peel strength lamination by adjusting pressure, temperature and/or dwell time of application. For example, in one embodiment of the invention, desired peel strength for the first lamination 36 can be provided by use of a lamination temperature of about 240-250 degree F. and the desired peel strength for the second lamination 38 can be provided by use of a lamination temperature about 30 degree F. hotter. Also, the second lamination 38 seal is typically run with a longer dwell time than the first lamination 36 seal. Still further, it is typical for the pressure applied to provide the desired peel strength of the second lamination 38 to be greater than the pressure applied to provide the desired peel strength of the first lamination.

The test liquid 14 can be any of a wide variety of test liquids, depending on the application. In an application where the test device 12 is a urine test strip, the test liquid 14 is test urine control.

The backing 18 is attached to at least a portion of the rearward facing surface of the rear wall. The backing 18 is stiffer than both the front wall 24 and the rear wall. By “stiffer” it is meant greater stiffness. Stiffness is the rigidity of an object—the extent to which it resists deformation in response to an applied force. The stiffness, k, of a body is a measure of the resistance offered by an elastic body to deformation. For an elastic body with a single degree of freedom (for example, stretching or compression of a rod), the stiffness is defined as k=F\δ where, F is the force applied on the body, δ is the displacement produced by the force along the same degree of freedom

The backing 18 can be made from a wide variety of materials, such as paper, cardstock, plastic, metal and wood. In a typical embodiment, the backing 18 is made from cardboard, such as 10 point cardboard having the specifications and features set forth below in TABLE 3:

TABLE 3 A white tag stock suitable for applications which require a stiff facestock with high internal strength. Basis Weight: 122 lb/ream (500 sheets 24″ × 36″) Caliper: 0.010 inches target Tensile: n/a Tear: MD 160 grams/sheet CD 170 grams/sheet Stiffness: MD 48 grams/cm, CD 24 grams/cm

The backing 18 can be made with additional stiffness by the application of a stiffening material, such as a stiffening polymer. In a typical embodiment, the stiffening polymer is a clear polypropylene applied to the rearward facing surface of the backing 18. Such clear polypropylene can be a biaxially oriented polypropylene having a total thickness of about 2.0 mils and a film thickness of about 1.2 mils and having the specifications and features set forth below in TABLE 4:

TABLE 4 Film: Biaxially Oriented Polypropylene Total Thickness: 2.00 mils Film Thickness: 1.20 mils +/− 5% Adhesive: Acrylic FEATURES Provides rigidity and extra strength for tag and label applications Offers enhanced gloss and clarity Excellent moisture, abrasion, chemical, UV light, and oil resistance PHYSICAL PROPERTIES Tensile Strength (LBS/IN) 24 PSTC*-131 (ASTM D3759**) Elongation (% At Break) 160 PSTC-131 (ASTM D3759) 180° Peel Adhesion (OZ/IN) 22 PSTC-101 (ASTM D3330***) APPLICATION TEMPERATURE 32° F. to 140° F. OPERATING TEMPERATURE −10° F. to 200° F. nominal range. Contact your STA representative to determine actual temperature range specific to a particular application. GOVERNMENT SPECIFICATIONS Conforms to FDA regulations 21 CFR 175.105 and 21 CFR 177.1520

The backing 18 has a rear face and a forward face facing the liquid holding device 16. The forward face of the backing 18 typically has an adhesive 40 thereon adhering the backing 18 to the liquid holding device 16. A typical adhesive 40 is set forth in TABLE 5:

TABLE 5 An all-purpose cold temperature adhesive featuring good initial tack and ultimate adhesion to a wide variety of substrates. FDA Compliance: Title 21, Section 175.105 of the Code of Federal Regulations (21 CFR 175.105). Compliance to this regulation permits the use of this adhesive in applications for which the adhesive either (1) is separated from the food by a functional barrier, which will prevent the migration of any of the adhesive components to the food, or (2) has incidental contact with food limited to the trace amount at the seams or the edges of the label. Type: Emulsion Acrylic Minimum Application Temperature: −20° F. Service Temperature Range: −65° F. to +200° F.

The backing 18 provides added strength/rigidity at the neck of the opening that helps prevent the access opening 29 from collapsing when applying pressure to start the peeling process.

Another advantage of the backing 18 is that it provides strength at the access opening 29 so that it is easy to slide in a test device 12 because the access opening 29 remains open.

Preferably, the backing 18 extends above the upper section 20 of the liquid holding device 16 to provide a convenient holding tab 42.

Thus, the backing 18 has three main purposes. It serves as a handle. It serves to provide the needed strength and rigidity at the access opening 29 to prevent collapse of the access opening 29 upon peeling. Lastly, it provides a surface to facilitate the start of the peeling process.

In a second aspect, the invention is method of testing a test device 12. The method of testing comprises the step of: a) holding the liquid holding apparatus 10 described above by the portion of a tab 42 extending above the liquid holding device 16; b) opening the access section 28; and c) inserting the test device 12 into the test liquid 14.

Depending on the application, the test device 12 can be a urine test strip (also termed a “urine dipstick”), a pH probe, a capillary tube, swab, etc. Once adequate separation is achieved, the test device 12 can be introduced into the liquid holding device 16. As the test device 12 is immersed into the test liquid, the fluid level rises—saturating each active portion with test liquid. The tolerances in the liquid holding device 16 provide maximum control as to which active portions 34 are immersed. This is important because some test device manufacturers recommend against flooding the last active portion on the test device 12. Once satisfactory immersion has been achieved, the test device 12 is removed from the liquid holding device 16 and the liquid holding apparatus 10 is discarded.

Exemplary of a commercial test device 12 for urine analysis is Siemens Mutlistix™ 10 SG which tests for glucose, bilirubin, ketone, specific gravity, blood, pH, protein, urobilinogen, nitrite, and leukocytes. The Siemens strip is about 14.6 cm (5¾ inches) long, about 0.5 cm (0.2 inch) wide, about 0.1 cm (0.04 inch) thick at the active portions, with the section of the test device 12 needing contact with the test liquid 14 being about 8.1 cm (4 3/16 inches) long.

In a third aspect, the invention is a method of forming the liquid holding apparatus 10 described above. The method of forming comprising the steps of: a) laminating the front wall 24 to the rear wall 26 except at the access section 28 to form the liquid holding device 16; b) placing test liquid 14 into the liquid holding device 16 through the access section 28; c) laminating the front wall 24 to the rear wall 26 at the access section 28; and d) laminating the front wall 24 to the rear wall 26 below the access section 28 with sufficient pressure, temperature and dwell that the seal formed thereby is stronger than the seal at the access section 28.

FIGS. 1-4 illustrate the process of forming a first embodiment wherein the lamination in step d) is not continuous to the end of the liquid holding device 16 opposite to the access opening 29.

FIGS. 5 and 6 illustrate the process of forming a second embodiment wherein the lamination of step d) is continuous to the end of the liquid holding device 16 opposite to the access section 28. FIG. 5 illustrates the lamination of step a) made to the entire geometry of the liquid holding device 16. FIG. 6 illustrates the lamination of step d) where the lamination of step d) is made to the entire geometry below the access section 28.

In all cases, the laminations of steps a) and d) can be accomplished using a variable strength sealing layer which provides desired lamination seal strengths by the application of different pressure, temperature and/or dwell conditions.

The invention provides a small portable liquid holding apparatus 10 that is easy to use and which minimizes spilling accidents.

Although the present invention is described in considerable detail with reference to certain preferred versions thereof, other versions are possible. Therefore the subject claims should not be limited to the preferred versions described.

All the features disclosed in this specification (including any accompanying claims, abstract, and drawings) may be replaced by alternative features serving the same, equivalent or similar purpose, unless each feature disclosed is one example only of a generic series of equivalent or similar features. 

1. A liquid holding apparatus for insertion of a test device into a test liquid, the liquid holding apparatus comprising: a) a liquid holding device for holding the test liquid, the liquid holding device having an upper section and a lower section, the liquid holding device comprising a front wall with a forward facing surface and a rear wall with a rearward facing surface, the liquid holding device having a periphery wherein the front wall and the rear wall are sealed together at the periphery, the upper section of the liquid holding device having an access section where the front wall can be detached from the rear wall to allow access for the test strip test device, at least a portion of the front wall being substantially transparent or translucent to allow visual inspection of a test device inserted into the liquid holding device; b) test liquid in the liquid holding device; and c) a backing attached to at least a portion of the rearward facing surface of the rear wall, the backing being stiffer than both the front wall and the rear wall.
 2. The apparatus of claim 1 wherein the test liquid is test urine control and the test device is a urine test strip.
 3. The apparatus of claim 1 wherein the liquid holding device is sufficiently long that all active portions of the strip test device can be immersed in the test liquid in the liquid holding device, and wherein the amount of test liquid in the liquid holding device is sufficient small that no test liquid flows out of the liquid holding device when the test device is inserted into the liquid holding device a sufficient distance that all active portions of the strip test device are in contact with the test liquid.
 4. The apparatus of claim 1 wherein the front wall is attached to the rear wall at the access section by a first lamination and the front wall is attached to the rear wall below the access section by a second lamination, the peel strength of the second lamination being greater than the peel strength of the first lamination.
 5. The apparatus of claim 1 wherein the access section provides an access opening which is wider than the liquid holding device below the access section.
 6. The apparatus of claim 5 wherein the width of the liquid holding device is tapered below the access opening.
 7. The apparatus of claim 1 wherein the liquid holding device is sufficiently long that a urine reagent strip which is 146 mm (5¾ inches) long, 5 mm (0.2 inch) wide, and 1 mm (0.04 inch) thick and having active portions, with the section having the active portions being 81 mm (4 3/16 inches) long, can be dipped in the liquid holding device with all of the active portions in contact with test liquid, and, optionally, wherein the liquid holding device 16 is at least 90 mm in length from the access section to the bottom of the liquid holding device.
 8. The apparatus of claim 7 wherein the volume of test liquid in the liquid holding device is sufficiently small that the urine reagent strip can be dipped therein without any test liquid leaking out of the liquid holding device, and, optionally, wherein the liquid holding device contains test liquid in an amount of no more than about 80% the total capacity of the liquid holding device.
 9. The apparatus of claim 1 wherein the backing has a rear face and a forward face facing the liquid holding device, and wherein the forward face of the backing has an adhesive thereon adhering the backing to the liquid holding device.
 10. The apparatus of claim 9 wherein the backing extends above the upper section of the liquid holding device to provide a holding tab.
 11. The apparatus of claim 10 wherein the front wall is attached to the rear wall at the access section by a first lamination, and the front wall is attached to the rear wall below the access section by a second lamination, the peel strength of the second lamination being greater than the peel strength of the first lamination.
 12. The apparatus of claim 1 wherein the backing is formed of cardboard.
 13. The apparatus of claim 12 wherein the cardboard is a 10 point cardboard.
 14. The apparatus of claim 12 wherein the rearward facing surface of the cardboard is coated with a polymer.
 15. A method of testing a test strip comprising the steps of: a) holding the apparatus of claim 10 by the tab extending above the liquid holding device; b) opening the access opening to the second lamination; and c) inserting the test strip test device into the test liquid.
 16. A method of forming the apparatus of claim 1 comprising the steps of: a) laminating the front wall to the rear wall except at the access section by a first lamination to form the liquid holding device; b) placing test liquid into the liquid holding device through the access section; c) laminating the front wall to the rear wall at the access section by a second lamination; and d) laminating the front wall to the rear wall below the access section by a third lamination with sufficient pressure, temperature and dwell that the seal formed thereby is stronger than the seal at the access section.
 17. A liquid holding apparatus for insertion of a test device into a test liquid, the liquid holding apparatus comprising: a) a liquid holding device for holding the test liquid, the liquid holding device having an upper section and a lower section, the liquid holding device comprising a front wall with a forward facing surface and a rear wall with a rearward facing surface, the liquid holding device having a periphery wherein the front wall and the rear wall are sealed together at the periphery, the upper section of the liquid holding device having an access section where the front wall can be detached from the rear wall to allow access for the test strip test device, at least a portion of the front wall being substantially transparent or translucent to allow visual inspection of a test device inserted into the liquid holding device; and b) test liquid in the liquid holding device; wherein the front wall is attached to the rear wall at the access section by a first lamination and the front wall is attached to the rear wall below the access section by a second lamination, the peel strength of the second lamination being greater than the peel strength of the first lamination.
 18. The liquid holding apparatus of claim 17 wherein second lamination is made to the entire geometry below the access section.
 19. The liquid holding apparatus of claim 17 wherein second lamination is made to the entire geometry below the access section and forms vertical striations. 